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      1 //  2016 and later: Unicode, Inc. and others.
      2 // License & terms of use: http://www.unicode.org/copyright.html
      3 /*
      4 *******************************************************************************
      5 *   Copyright (C) 2010-2016, International Business Machines
      6 *   Corporation and others.  All Rights Reserved.
      7 *******************************************************************************
      8 *   file name:  ucharstriebuilder.h
      9 *   encoding:   UTF-8
     10 *   tab size:   8 (not used)
     11 *   indentation:4
     12 *
     13 *   created on: 2010nov14
     14 *   created by: Markus W. Scherer
     15 */
     16 
     17 #ifndef __UCHARSTRIEBUILDER_H__
     18 #define __UCHARSTRIEBUILDER_H__
     19 
     20 #include "unicode/utypes.h"
     21 #include "unicode/stringtriebuilder.h"
     22 #include "unicode/ucharstrie.h"
     23 #include "unicode/unistr.h"
     24 
     25 /**
     26  * \file
     27  * \brief C++ API: Builder for icu::UCharsTrie
     28  */
     29 
     30 U_NAMESPACE_BEGIN
     31 
     32 class UCharsTrieElement;
     33 
     34 /**
     35  * Builder class for UCharsTrie.
     36  *
     37  * This class is not intended for public subclassing.
     38  * @stable ICU 4.8
     39  */
     40 class U_COMMON_API UCharsTrieBuilder : public StringTrieBuilder {
     41 public:
     42     /**
     43      * Constructs an empty builder.
     44      * @param errorCode Standard ICU error code.
     45      * @stable ICU 4.8
     46      */
     47     UCharsTrieBuilder(UErrorCode &errorCode);
     48 
     49     /**
     50      * Destructor.
     51      * @stable ICU 4.8
     52      */
     53     virtual ~UCharsTrieBuilder();
     54 
     55     /**
     56      * Adds a (string, value) pair.
     57      * The string must be unique.
     58      * The string contents will be copied; the builder does not keep
     59      * a reference to the input UnicodeString or its buffer.
     60      * @param s The input string.
     61      * @param value The value associated with this string.
     62      * @param errorCode Standard ICU error code. Its input value must
     63      *                  pass the U_SUCCESS() test, or else the function returns
     64      *                  immediately. Check for U_FAILURE() on output or use with
     65      *                  function chaining. (See User Guide for details.)
     66      * @return *this
     67      * @stable ICU 4.8
     68      */
     69     UCharsTrieBuilder &add(const UnicodeString &s, int32_t value, UErrorCode &errorCode);
     70 
     71     /**
     72      * Builds a UCharsTrie for the add()ed data.
     73      * Once built, no further data can be add()ed until clear() is called.
     74      *
     75      * A UCharsTrie cannot be empty. At least one (string, value) pair
     76      * must have been add()ed.
     77      *
     78      * This method passes ownership of the builder's internal result array to the new trie object.
     79      * Another call to any build() variant will re-serialize the trie.
     80      * After clear() has been called, a new array will be used as well.
     81      * @param buildOption Build option, see UStringTrieBuildOption.
     82      * @param errorCode Standard ICU error code. Its input value must
     83      *                  pass the U_SUCCESS() test, or else the function returns
     84      *                  immediately. Check for U_FAILURE() on output or use with
     85      *                  function chaining. (See User Guide for details.)
     86      * @return A new UCharsTrie for the add()ed data.
     87      * @stable ICU 4.8
     88      */
     89     UCharsTrie *build(UStringTrieBuildOption buildOption, UErrorCode &errorCode);
     90 
     91     /**
     92      * Builds a UCharsTrie for the add()ed data and char16_t-serializes it.
     93      * Once built, no further data can be add()ed until clear() is called.
     94      *
     95      * A UCharsTrie cannot be empty. At least one (string, value) pair
     96      * must have been add()ed.
     97      *
     98      * Multiple calls to buildUnicodeString() set the UnicodeStrings to the
     99      * builder's same char16_t array, without rebuilding.
    100      * If buildUnicodeString() is called after build(), the trie will be
    101      * re-serialized into a new array.
    102      * If build() is called after buildUnicodeString(), the trie object will become
    103      * the owner of the previously returned array.
    104      * After clear() has been called, a new array will be used as well.
    105      * @param buildOption Build option, see UStringTrieBuildOption.
    106      * @param result A UnicodeString which will be set to the char16_t-serialized
    107      *               UCharsTrie for the add()ed data.
    108      * @param errorCode Standard ICU error code. Its input value must
    109      *                  pass the U_SUCCESS() test, or else the function returns
    110      *                  immediately. Check for U_FAILURE() on output or use with
    111      *                  function chaining. (See User Guide for details.)
    112      * @return result
    113      * @stable ICU 4.8
    114      */
    115     UnicodeString &buildUnicodeString(UStringTrieBuildOption buildOption, UnicodeString &result,
    116                                       UErrorCode &errorCode);
    117 
    118     /**
    119      * Removes all (string, value) pairs.
    120      * New data can then be add()ed and a new trie can be built.
    121      * @return *this
    122      * @stable ICU 4.8
    123      */
    124     UCharsTrieBuilder &clear() {
    125         strings.remove();
    126         elementsLength=0;
    127         ucharsLength=0;
    128         return *this;
    129     }
    130 
    131 private:
    132     UCharsTrieBuilder(const UCharsTrieBuilder &other);  // no copy constructor
    133     UCharsTrieBuilder &operator=(const UCharsTrieBuilder &other);  // no assignment operator
    134 
    135     void buildUChars(UStringTrieBuildOption buildOption, UErrorCode &errorCode);
    136 
    137     virtual int32_t getElementStringLength(int32_t i) const;
    138     virtual char16_t getElementUnit(int32_t i, int32_t unitIndex) const;
    139     virtual int32_t getElementValue(int32_t i) const;
    140 
    141     virtual int32_t getLimitOfLinearMatch(int32_t first, int32_t last, int32_t unitIndex) const;
    142 
    143     virtual int32_t countElementUnits(int32_t start, int32_t limit, int32_t unitIndex) const;
    144     virtual int32_t skipElementsBySomeUnits(int32_t i, int32_t unitIndex, int32_t count) const;
    145     virtual int32_t indexOfElementWithNextUnit(int32_t i, int32_t unitIndex, char16_t unit) const;
    146 
    147     virtual UBool matchNodesCanHaveValues() const { return TRUE; }
    148 
    149     virtual int32_t getMaxBranchLinearSubNodeLength() const { return UCharsTrie::kMaxBranchLinearSubNodeLength; }
    150     virtual int32_t getMinLinearMatch() const { return UCharsTrie::kMinLinearMatch; }
    151     virtual int32_t getMaxLinearMatchLength() const { return UCharsTrie::kMaxLinearMatchLength; }
    152 
    153     class UCTLinearMatchNode : public LinearMatchNode {
    154     public:
    155         UCTLinearMatchNode(const char16_t *units, int32_t len, Node *nextNode);
    156         virtual UBool operator==(const Node &other) const;
    157         virtual void write(StringTrieBuilder &builder);
    158     private:
    159         const char16_t *s;
    160     };
    161 
    162     virtual Node *createLinearMatchNode(int32_t i, int32_t unitIndex, int32_t length,
    163                                         Node *nextNode) const;
    164 
    165     UBool ensureCapacity(int32_t length);
    166     virtual int32_t write(int32_t unit);
    167     int32_t write(const char16_t *s, int32_t length);
    168     virtual int32_t writeElementUnits(int32_t i, int32_t unitIndex, int32_t length);
    169     virtual int32_t writeValueAndFinal(int32_t i, UBool isFinal);
    170     virtual int32_t writeValueAndType(UBool hasValue, int32_t value, int32_t node);
    171     virtual int32_t writeDeltaTo(int32_t jumpTarget);
    172 
    173     UnicodeString strings;
    174     UCharsTrieElement *elements;
    175     int32_t elementsCapacity;
    176     int32_t elementsLength;
    177 
    178     // char16_t serialization of the trie.
    179     // Grows from the back: ucharsLength measures from the end of the buffer!
    180     char16_t *uchars;
    181     int32_t ucharsCapacity;
    182     int32_t ucharsLength;
    183 };
    184 
    185 U_NAMESPACE_END
    186 
    187 #endif  // __UCHARSTRIEBUILDER_H__
    188